A humidification apparatus having control of humidity as a main function is required for a pleasant life of the human being and is essential to prevent a variety of types of diseases and to maintain health. In Korea, the volume of a household humidifier market approaches 100 billons won, and the global market volume of the household humidifier approaches several trillion won. Accordingly, the household humidifier of home appliances has a relatively large market volume compared to low recognition. In particular, alternate product markets, such as charcoal and natural evaporation devices, are significantly increased due to chronic problems and inconvenience, such as a safety problem and the difficulty of cleaning and management in existing humidification apparatuses. This reveals that the humidifier is not simple taste consumer goods, but daily consumer goods. In particular, people's interest in health and well-being is increased as economy is advanced, and an individual interest and investment in a pleasant environment are increased in order to prevent diseases and to lead a healthy life as a burden of a medical cost is increased. This is significant in the humidifier market. In China, the humidifier market tends to be remarkably increased.
The humidifier is basically divided into a cold mist method for direct spraying vapor using ultrasonic waves/nozzle, a warm mist method for spraying vapor by heating, and an evaporation type for natural humidification through the forced circulation of air to an evaporation plate having a wide surface area.
A direct spray method, such as an ultrasonic humidification method, is advantageous in that maintenance is relatively easy because residues rarely remain in a humidification module and power consumption is low, but is problematic in that health it may be fatal to health because compounds of calcium, heavy metals and/or virus remaining in water is introduced into air. In particular, germicides are used for sterilization because virus is directly sprayed into air when the virus is reproduced. A germicide accident in the ultrasonic humidifier, which lost the life of several tens of the old and the infirm and infants in 2011 and gave us a great shock, speaks volume about a problem of the direct humidification method. The sterilization components of humidifier germicides chiefly include polyhexamethylene guanidine (PHMG), oligo(2-)ethoxy ethoxyethyl guanidine chloride (PGH), and methylchloroisothiazolinone (CMIT). Such materials are used for various products, such as shampoo and water tissues, because they have skin toxicity which is about 1 of a 5˜10 percentage point compared to other germicides, but no sanction was not applied to the materials until victims were generated because research had not been carried out on toxicity generated when the materials were inhaled by a respiratory organ. In the case of PHMG and PGH, related companies suffered punishments after the harmfulness of PHMG and PGH was proven in clinical tests, and the distribution of all humidifier germicides was stopped. In U.S.A., Europe, and China in which many compounds of calcium is present in tap water, the problem of the ultrasonic humidifier has already come to the fore because compounds of calcium included in water are sprayed into air in a fine dust form apart from the germicide problem.
In contrast, the heating type humidifier is advantageous in that it has a sterilization action because water is heated to a high temperature and humidified and it is sanitary because a variety of types of alien substances, such as compounds of calcium included in water, are rarely introduced into air. However, the heating type humidifier is very inconvenient because residues in water adhere to a heating plate after pure water is supplied and thus the heating plate must be periodically cleaned. In particular, if many compounds of calcium are included in tap water as in U.S.A., Europe, and China, solid compounds of calcium are thickly deposited on the heating plate even after use of several days, and it is very inconvenient to remove the compounds of calcium deposited on the heating plate.
An evaporation type humidifier of an air wash type in which several tens of disks overlap to widen a surface area and humidification is performed by forcedly circulating air recently gains great popularity. Like the ultrasonic humidifier, the evaporation type humidifier has a concern about virus reproduction, but is relatively safe because alien substances, such as virus or compounds of calcium, are not introduced into air. However, such a kind of humidifier has disadvantages in that a stack structure of several tens of disks for widening a surface area of an evaporation plate makes it difficult cleaning and maintenance and the amount of humidification is relatively low. In order to supplement such disadvantages, strong air circulation needs to be generated using a fan, which may lead to a noise problem. Furthermore, a special detergent is used to clean an evaporation disk stack module. There is an evaporation type humidifier using a disposable module without using the evaporation disks due to the difficulty of such cleaning. All of existing humidification apparatuses on the market do not satisfy both the core elements “safety” and “cleaning and maintenance.”